Fourteen avermectin B2 a aglycon derivatives were designed and synthesized after removing the oleandrose disaccharide of avermectin B2 a.Their structures were characterized by’H NMR,13 C NMR,HMRS.Preliminary bioassay...Fourteen avermectin B2 a aglycon derivatives were designed and synthesized after removing the oleandrose disaccharide of avermectin B2 a.Their structures were characterized by’H NMR,13 C NMR,HMRS.Preliminary bioassays indicated that these compounds exhibited good insecticidal activity against diamondback moth at 200 mg/L,with mortality no less than 90%.Compounds 10 b,12 a,12 c,17 demonstrated good acaricidal activity against the adult mites,larvae,and good inhibition rate of hatching to mite eggs of Tetranychus cinnabarinus.Compounds 5,10 b,10 c exhibited excellent fungicidal activity against fourteen fungal pathogens in vitro.3 D-QSAR analysis showed that the fungicidal activity of avermectin B2 a aglycon derivatives would be increased when a negatively charged and bulky group was introduced at 13-position,which will be instructive for the further modification of avermectin B2 aaglycon.展开更多
To provide a test platform for Electronic Warfare (EW) system, it is needed to simulate the radar received Intermediate Frequency (IF) signals and radar system functions.This letter gives a description of a radar syst...To provide a test platform for Electronic Warfare (EW) system, it is needed to simulate the radar received Intermediate Frequency (IF) signals and radar system functions.This letter gives a description of a radar system simulation software developed for frequencyphase scanning three-dimensional (3-D) radar. Experimental results prove that the software could be used for system evaluation and for training purposes as an attractive alternative to real EW system.展开更多
目的:探讨微RNA-29b(microRNA-29b,miR-29b)在骨尤文肉瘤细胞中的表达及其对尤文肉瘤细胞体外侵袭和微血管拟态形成能力的影响。方法:采用实时荧光定量PCR法检测miR-29b在骨尤文肉瘤A673、SKES-1及RD-ES细胞中的表达水平。通过转染外源...目的:探讨微RNA-29b(microRNA-29b,miR-29b)在骨尤文肉瘤细胞中的表达及其对尤文肉瘤细胞体外侵袭和微血管拟态形成能力的影响。方法:采用实时荧光定量PCR法检测miR-29b在骨尤文肉瘤A673、SKES-1及RD-ES细胞中的表达水平。通过转染外源性miR-29b模拟片段(mimic)使A673和SK-ES-1细胞中miR-29b过表达,然后采用Transwell小室侵袭实验和体外血管拟态形成实验分别检测miR-29b过表达对A673及SK-ES-1细胞侵袭和血管拟态形成能力的影响,并采用蛋白质印迹法检测过表达miR-29b后尤文肉瘤A673和SK-ES-1细胞中信号转导与转录激活因子3(signal transducer and activator factor of transcription 3,STAT3)及其磷酸化STAT3(phosphorylated STAT3,p-STAT3)蛋白表达水平的变化。结果:与人间充质干细胞(对照组)相比,骨尤文肉瘤A673、SK-ES-1和RD-ES细胞中miR-29b表达水平呈下降趋势(P<0.01,P<0.01,P<0.05)。通过转染外源性miR-29b mimic,恢复A673及SK-ES-1细胞中miR-29b的表达后(P值均<0.01),2种细胞的体外侵袭能力均较对照组明显降低(P值均<0.01),体外新生血管形成能力也较对照组明显降低(P<0.05,P<0.01),而且尤文肉瘤细胞中STAT3及p-STAT3的表达水平均明显下调(P值均<0.01)。结论:尤文肉瘤细胞中miR-29b低表达,过表达miR-29b能够明显抑制尤文肉瘤细胞的体外侵袭及新生血管拟态形成,该作用可能与靶向调控STAT3通路有关。展开更多
基金supported by the National Key R&D Program of China (No.2018YFD0200100)
文摘Fourteen avermectin B2 a aglycon derivatives were designed and synthesized after removing the oleandrose disaccharide of avermectin B2 a.Their structures were characterized by’H NMR,13 C NMR,HMRS.Preliminary bioassays indicated that these compounds exhibited good insecticidal activity against diamondback moth at 200 mg/L,with mortality no less than 90%.Compounds 10 b,12 a,12 c,17 demonstrated good acaricidal activity against the adult mites,larvae,and good inhibition rate of hatching to mite eggs of Tetranychus cinnabarinus.Compounds 5,10 b,10 c exhibited excellent fungicidal activity against fourteen fungal pathogens in vitro.3 D-QSAR analysis showed that the fungicidal activity of avermectin B2 a aglycon derivatives would be increased when a negatively charged and bulky group was introduced at 13-position,which will be instructive for the further modification of avermectin B2 aaglycon.
文摘To provide a test platform for Electronic Warfare (EW) system, it is needed to simulate the radar received Intermediate Frequency (IF) signals and radar system functions.This letter gives a description of a radar system simulation software developed for frequencyphase scanning three-dimensional (3-D) radar. Experimental results prove that the software could be used for system evaluation and for training purposes as an attractive alternative to real EW system.
文摘目的:探讨微RNA-29b(microRNA-29b,miR-29b)在骨尤文肉瘤细胞中的表达及其对尤文肉瘤细胞体外侵袭和微血管拟态形成能力的影响。方法:采用实时荧光定量PCR法检测miR-29b在骨尤文肉瘤A673、SKES-1及RD-ES细胞中的表达水平。通过转染外源性miR-29b模拟片段(mimic)使A673和SK-ES-1细胞中miR-29b过表达,然后采用Transwell小室侵袭实验和体外血管拟态形成实验分别检测miR-29b过表达对A673及SK-ES-1细胞侵袭和血管拟态形成能力的影响,并采用蛋白质印迹法检测过表达miR-29b后尤文肉瘤A673和SK-ES-1细胞中信号转导与转录激活因子3(signal transducer and activator factor of transcription 3,STAT3)及其磷酸化STAT3(phosphorylated STAT3,p-STAT3)蛋白表达水平的变化。结果:与人间充质干细胞(对照组)相比,骨尤文肉瘤A673、SK-ES-1和RD-ES细胞中miR-29b表达水平呈下降趋势(P<0.01,P<0.01,P<0.05)。通过转染外源性miR-29b mimic,恢复A673及SK-ES-1细胞中miR-29b的表达后(P值均<0.01),2种细胞的体外侵袭能力均较对照组明显降低(P值均<0.01),体外新生血管形成能力也较对照组明显降低(P<0.05,P<0.01),而且尤文肉瘤细胞中STAT3及p-STAT3的表达水平均明显下调(P值均<0.01)。结论:尤文肉瘤细胞中miR-29b低表达,过表达miR-29b能够明显抑制尤文肉瘤细胞的体外侵袭及新生血管拟态形成,该作用可能与靶向调控STAT3通路有关。
